How do I edit lists when the edit dots in the corner have completely disappeared?

There used to be 3 dots in the corner that would give you the option to edit or add notes to titles that are in a list but this seems to have completely disappeared. Editing lists seem to get more and more difficult every time I try to do so (I have tried doing this on both my phone app and on a desktop computer but it just wont let me). I have tried following instructions given to me but these three dots are no where to be seen